William morrison



NQMOaeL if W. MORRISON.

BRUSH MOLD.

No. 532,210. PatentedJan. 8, 1895.

UNITED STATES PATENT OFFICE...

WILLIAM MORRISON,

OF LANSINGBURG, NEW YORK, ASSIGNOR To EMMA MORRISON, OF SAME PLACE.

BRUSH-MOLD.

SPECIFICATION forming part of Letters Patent lll'o. 532,210, dated January 8, 1895. Application filed June 18, 1894- Serial No. 514,834:- (No model.)

- drawings and the letters of. reference marked thereon, which form a part of this specification.

Similar letters refer to similar parts in both figures therein.

Figure l of the drawings is a central, vertical, longitudinal section of my improved mold. Fig. 2 isa view in side elevation of one of the plungers detached. 7

My invention relates to improvements in brush-molds for forming of plastic material the bristle-supporting head-block of a brush.

The Object of my invention is to facilitate the removal of the brush from the mold without breakage.

The mold comprises the base-plate A, and the crown-plate B adapted to be superimposed upon the base-plate and held thereon in exact position by the dowel-pins G which are supported by the base-plate and enter suitable apertures in thecrown-plate.

The crown-plate is cut away on its inner side B' to conform to theshape of the top surface and upper side edge of the molded portion of the brush. The walls of such inner side may be provided with any design, sunken or in relief, with which it is desired to ornament the back of the brush. The base-plate A is similarly cut away on its inner side A to conform to the shape of the bottom surface and lower side edge of the molded article. The base-plate may also be provided with an ornamental design, when desired.

The base-plate is adapted for use in mold in g brushes by a plurality of bristle-sockets or recesses A arranged after the usual, or any known, method, and adapted to receive and support the bristles with their upper ends in the lower part of the mold cavity between the two plates or mold-sections,'in the usual well known manner. The base-plate is also proing from the molding surface of the plate ontirely through the same to its bottom surface. In each of these apertures, I insert a plunger D of suitable size to fit the aperture and adapted to be movable longitudinally therethrough. The inner end of the plungeris flush with the molding surface of the base-plate and such inner end has a molding face D the base-plate around the aperture.

The operation of the device is as follows: The base-plate is first prepared by the insertion of bristles in the recesses A in the base plate, after which the bristles are trimmed so that their ends project uniformly into the mold cavity the distance it is desired to have them embedded in the brush-head. A small quantity of the plastic composition of which the brush is formed, may then be worked by hand between and around the projecting ends ofthe bristles to insure the complete embedding of such ends in the brush-head. The plunger or plungers D being in position, the mold cavity is then filled with the melted or partly melted composition which is round ed up in approximately the form of thecompleted brush; and the crown-plate superimposed thereon in the proper position determined by the dowel-pins. The mold is then complete, and is subjected to pressure in a press until the composition sets or hardens, whereupon the mold may be opened and the brush removed. The brush is removed from the baseplate by driving the plunger or plungersD- a short distance into the mold cavity until the brush is forced from its seatin the base-plate.

Theplunger may be of the exact length to with the respective surfaces of the base-plate. When so formed, the plunger can be operated manner.

By projecting the lower end of the plunger as shown at D the projection is easily accessible, and the plunger can be driven into the mold cavity by means of a hammer or vided with one or more apertures D extendjust fill the aperture, having its ends flash by a small follower-pin, or in any known corresponding with the molding surface of below the bottom surface of the base-plate,

. the base-plate similarly contracted to form a plungers in apertures formed in the recessed end of the plate. The molding face of the plunger may be made of any desired. size by locating one or more of the bristle-recesses in the plunger, as shown at D The number and position of the plungers may be varied according to the quality of the composition employed, or the style of article formed therefrom. l

I am aware that a mold for casting metal has been provided with a plurality of plungers for removing the casting from the mold, and I make no claim to such a device broadly. It is well known to those skilled in the art of making molded brushes, that great difficulty is experienced in removing the molded brush from the base-plate of the mold. This is largely due to the fact that the plastic composition is subjected to extreme pressure in the mold, which pressure forces the composition so tightly between and around the bristles in the upper portions of the recesses in the base-plate, as to cause the bristles to become wedged tightly by the composition within the recessed portion of the mold.

As heretofore practiced, it has been customary to construct a brush-mold in three parts or sections, the middle plate or section having an aperture for the bristle'receiving portion of the base-plate, and the walls of the aperture being chamfered along their upper edges so as to underlie the periphery of the head-portion of the molded brush, and serve as a lifting device for withdrawing the bristles from the recesses.

By reason of the extreme pressure, every joint in the mold forms a fillet or rib on the molded article, which must be removed after the article is taken from the mold; and it will readily be seen that the use of a middle plate underlying the edge of the brush-head produces a fillet along the edge of the under face of the brush-head in close proximity to the bristles and in a position which renders its removal dilficult without cutting or injuring the bristles.

By providing the base-plate with one or more plungers in its bristle-receiving portion where-the greatest resistance to the withdrawal of the brush occurs, I am able to wholly dispense with the middle-plate or section formerly employed, the crown-plate and base-plate being together adapted to wholly form the mold cavity, with a single joint or line of division. I am therefore able to avoid the formation of a fillet on the under face of the brush-head, except such as is formed by the plunger, which is not conspicuous, and 1s concealed by the surrounding bristles, rendering its removal unnecessary.

The only fillet requiring removal is that which marks the dividing line between the base and crown-plates, and which is on the extreme edge of the brush, in a position to be easily and safely removed.

The bunches of bristles are so closely located that a plunger of a size adapted to be inserted between two neighboring recesses would present a face of such small area as to be likely to chip or break the hardened and brittle composition. By forming one or more of the bristle recesses in the plunger itself, the plunger-face can be made of any desired area, insuring the safe removal of the brush from the mold.

What I claim as new, and desire to secure by Letters Patent, is Y In a brush-mold, the combination with the crown-plate, of a base-plate provided with bristle-recesses and a plunger-aperture extending through the recessed portion of the WILLIAM MORRISON.

Witnesses:

Gno. A. MosHER, FRANK C. CURTIS. 

